초록 ▼

A sensing system for a vibration isolation table. A sensor responsive to the position of the tabletop is spaced apart from the tabletop and provides an output corresponding to the position of the tabletop. The output is modified to provide a control signal and a valve responsive to the modified sign

A sensing system for a vibration isolation table. A sensor responsive to the position of the tabletop is spaced apart from the tabletop and provides an output corresponding to the position of the tabletop. The output is modified to provide a control signal and a valve responsive to the modified signal controls the flow of air into and out of an air isolator which supports the load.

대표청구항 ▼

An apparatus for monitoring and controlling the position of a pneumatically supported load at least one air isolator controlling the movement of the mass in the XY plane which comprises: a sensor adapted to provide a sensor signal corresponding to the displacement of the supported load in the x-y pl

An apparatus for monitoring and controlling the position of a pneumatically supported load at least one air isolator controlling the movement of the mass in the XY plane which comprises: a sensor adapted to provide a sensor signal corresponding to the displacement of the supported load in the x-y plane, the sensor signal varying depending upon the displacement of the supported load; means to process the sensor signal and to provide a modulated, two-state, pulsed output signal at a modulation frequency, the duty cycle of the output signal determined by the sensor signal; a two-state pneumatic valve actuated by the output signal such that there is a net flow of air into or out of the air isolator when the load is not at its zero position, whereby as the load moves to its zero position the net flow of air into or out of the air isolator decreases; and means to control the modulation frequency such that it is higher than the resonant frequency of the free mass/pneumatic system to ensure that the isolated mass responds only to the net gas flow averaged over may alternation cycles and does not respond to the input and output which occurs in the course of each cycle.